Balanced plug valve



Oct. 30, R H, WUNN v BALANCED PLUG VALVE i INVNTOR. Richard H. Wann.

Filed March 19, 194e /ITTORNEYl Patented Oct. 30, 1951 U'NiTsEi-D TS TAT-TES PATfENT 0F FICE BALANOED I LUG'VALVE Richard-'H; Wunn, Bellflower, Calif.

.ApplicatiorrMarch 19, 1946,'Seria'l No. v655,615

3fClaims. 1 This invention relates tto 4a novel vbalanced valve and particularly a fmeans of balancing vua rplug valve.

An object of my invention Vis to provide a novel balanced plug valve in Which-the plug is ballt anced by `means ofi-chambers 4provided iboth: above and below -the plug ofthevalv'e, ltheselchambers being interconnected, and also vconnected to lpressure cylinders, ithese Acylinders being fopen `Ato the pressure `in the line, and 'fthe t'area `on .the top and bottom fof the plugbeing iequalized .by -a piston farea inthe b'ottomfof 'the fplug.

Still another object is 'to provide fa novel `Abail- 1anced plug vvalve iin which 4the Valve is .slightly cammed off-.of its .seat on rotation ofthe .control handle.

nlfeature of 'myinvention resides in `:thespring disk `Which :bears .against .the plug, vand Iyeldably lpresses the 'plug onto its seat,

Still; another ifeature vis.to..provide :a novel bal- Vance'd plug yalue with means 'of :introducing :a .'luidf-to the #various Vbalancing :chambers in sthe valve, `the chambers `being. fall .interconnected Aso that allofithesechambersand connecting ducts can be lled-withia suitable .-iluid from zonezsource.

`.Other objects, advantagesand .features of int rvention may appear from the accompanying drawing, the..:.subj.oineddetailed description .and

`.the .appendednclaims In :the :drawing: Figure Il is .fa .longitudinal-.sectional -view-of. one type `of valve embodying A.rny novel construction.

Figure 2 `is uagplan viewpfithefsprng disk. -Figure 3.is .-'a sbottom aplan .view-of the control 1 shaft.

`and the other the-outlet. 'For 4purposes of this description, it -isfa-ssumed thfat the port 2 is Ethe inlet, fand'the "port -3 is-theoutl'et. A transverse port #l extends through Vvthe bedy of the valve, `and 1thisport is controlledby the'ftapere'cl 1plug=5. The plug 5 is mounted inathe longitudinal bore 6 inthe valve body. A cap .'I closes the `lower end.

of the bore 6, and this capmaybe threadedinto the body of the valve. A spring disk `8"rests on 'the cap "I and bear-s against'the bottom -ofv the Aplug v5 `to urge this plug upwardly into its seat. 'l'fhedisk is yprovided With a number 'of ports or perforations 9 extending therethrough, the `purpose of these perforations being 4to permit the free Ypassage of fluid, which will be further described.

An annular 'fluid chamber III) is formed in the ,plug '5 adjacent fthe Ilowerend thereof, and this lchamber is connected with 'a'cham'ber I I below the plug by means 'of the ducts I2. The oil -in.- take :Iitting "I3 is connectedto the chamber III through aport lll, -Whichopens bel'owthe'spring disk "S and thenceto the Vcham-ber II :through'the perforatons 9. An'annular'pressure chamber `I5 is provided inthe body of the valve'atthe upper end ofthe plug f5. Th'e'chambers 'III `and vI5 vare connected by 'ducts IS, and these ducts may be in the plug 5 or in `the 'bodyof thevalve I, as desired. A pair -of cylinders I'I, I8 areformed Ain the body uof the Valve, the cylinder II Vbeing l'adjacent rthe 4port Y2 and the cylinder -IB being adjacent'theport 3. Each of the pressure cylinders Il, I8 lare provided with a-pistonV I9, -20 respectively. A 'duct '21 extends from the bore 4 iinto the bottom vof the cylinder A'-Il'I, Aand a similar duct 22'extends into the cylinder I8. Thecylinders Il, I8 are each connected vto the chamber .l5 by a duct '23, 24 respectively, so thatpressure `exerted vin either kor both of these cylinders `vvill .be 'transmitted to the 'chamber I5.

It will be evident 'from the foregoing description that 4thechambers I0, `I'I and I5, as well as 'the vcylinders I'I and I8, can-all be lled with an oil, 4grease or the like from the 'fitting I3; When all of these chambers and vcylinders are filled Awith oil vor grease, any 'pressure exerted on the 'pistons I9 and Y20 lvv-ill be `transmitted to the `chambers I0, I'I and I5 to balance the pressure `von theplug. 4When theplug-is in closed posistion, if there is back pressure in 'the line, the piston 20 will transmit #this "back pressure tothe cylinder VvI8, vand -this pressure is then trans- 'mitted `to the chambers I0, II 'and vI5 to again `balance the pressure on'the plug 5. When such Vback pressure occurs, it is desirable to=eXert`pres sure within 'the vhorizontal bore of the plug '5, .Land 'for this purpose I provide a piston 25, the .cylinder bore of which is open at the top tothe 'interiorof Vtl'ie'p'lug' and the bottom 'of -the bore of this piston is open to the chamber II, substantiallyas shownfin Figure 1, lBack ypressure at the port 3 lwill thus be exerted on r-the bottom of the pistonA 25, forcing this Apistonupwardly to the ,'.position shown in Fig. 1,and '-thusexerting the' pressure 'within'fthe-plug V'When' back pressure occurs in the valve, the plug 5 tends to be forced downwardly and oi of its seat. To balance this back pressure and to hold the plug onto its seat, the piston 25 is moved upwardly, as previously described, and pressure is thus exerted against the upper surface of the horizontal bore in the plug, and this pressure, together with the upward pressure in the chamber I0, will balance the downward pressure in the chamber I5. The area on the top of the plug 5 against which pressure is exerted to force the plug off of its seat is equalled by the area on the bottom of the plug 5 within the chamber I0, plus the area of the piston 25. The plug 5 is rotated by means of the handle shaft 26, which extends through a cap 21 threaded onto 4the top of the -body I. A thrust bearing 28 bears against the cap 21 and serves to properly position the plug 5 on its seat. A packing 29 surrounds the shaft 26; and may be of usual and well-known construction. The shaft 26 extends into the top of the plug 5, and is centered by the pin 3U. A pair of wedge shaped .wings 3| extend from the shaft 26, and loosely fit into wedge shaped grooves 32 in the top of the plug 5. Thus, when the shaft 26 is rotated, there is a small amount of lost motion between the shaft and the plug, and this lost motion causes the tapered wing 3| to press against the tapered wall of the groove 32, thus camming the plug 5 downwardly a Very slight amount but enough to free the plug on its seat. If the plug 5 should become stuck due to standing in one position for a long period of time, it is possible to push this plug off of its seat by screwing the cap 21 downwardly. Since the shaft 26 bears against the cap 21, it will be evident that a slight amount of downward movement of this cap will free the plug 5 and permit it to rotate.

In Figure 7 I have shown a ilre nozzle embodying the same features of construction as far as the balancing of the plug is concerned. The re nozzle consists of a body 35 and a transversely mounted plug 36 in the body. Balancing chambers 31, 38 are provided on each end of the plug, and these chambers are connected by ducts 39. A pair of cylinders 40, 4I are provided in the body of the valve, and the inner end of these cylinders are connected to the chambers 31, 3B respectively. Each of the cylinders is provided with a. piston 42, 43 respectively, and the outer end of the cylinders are open t the main fluid passage 44 of the valve through ducts 45, 46'respectively. A spring disk 41 bears against the bottom of the plug 36 and urges the same against its seat. An oil or grease fitting 48 permits all of the chambers and cylinders to be lled with oil or grease from this one source. The nozzle tip 49 is usual and well known for this type of valve, and the detailed construction thereof forms no part of this invention. The plug 36 is rotated by means of the shaft 50, which in turn is rotated by the handle A cap 52 is threaded onto the body of the valve, and serves to hold the shaft 50 and handle 5| in assembled position. The coupling arrangement between the shaft 50 and the plug 36 is the same as that previously described as interconnecting the shaft 26 and the plug 5. When the chambers I0 and I5 are lled with oil or grease, this oil will be forced around the plug 5, that is onto the seat of the plug, thus lubricating the same and'permitting the plug to move freely.

Having described my invention, I claim:

1. A balanced plug valve comprising a body, said body having a fluid passage extending therethrough, a plug mounted in said passage, said plug having a transverse port extending therethrough, said body having a balance chamber above and below said plug, said body having ducts therein interconnecting said chambers, said body having a cylinder therein, said body having still another duct extending from the cylinder to one of Vsaid chambers, a piston in said cylinder, said body having an opening extending from the iiuid passage to said cylinder, a fitting in the body, said fitting being connected with one of said chambers, said plug having a cylinder bore therein, a balancing piston mounted in the cylinder bore, said cylinder bore being open at one end to the interior of the plug andat the other end to said chamber below the plug.

2. A balanced plug valve comprising a body, 'said body having a fluid passage extending therethrough, a tapered plug rotatably mounted in said passage, said body having a balance chamber above said plug and a second balance chamber below said plug, said body having ducts therein connecting both of said chambers, a shaft rising from said plug, a cap threaded onto the body, said shaft shouldering against the cap whereby downward movement of the cap will press against the plug and free said plug in its seat, said body having a cylinder therein, said body having another duct extending from said cylinder to one of said chambers, a piston in the cylinder, said body having an opening extending from the fluidpassage to said cylinder, and a fitting in the body, said tting being connected with one of said chambers, said plug having a cylinder bore therein, a balancing piston mounted in said cylinder bore, said cylinder bore being open at one end to the interior of the plug and at the other end to said chamber below the plug.

3. A balanced plug valve comprising a body, said body having a fluid passage extending therethrough, a tapered plug mounted in said passage and having a port therethrough alignable with said passage, said body having a chamber above and below said plug, said body having ducts therein interconnecting said chambers, said plug having a cylinder bore therein, a piston mounted in' said cylinder bore, said cylinder bore being open at'one end to the lower chamber, and at the other end to said port in the plug, the area of said piston exposed to the port equalizing the area of the-bottom of the plug with that of the -top of the plug, said body having a cylinder therein, said body having still another duct extendingI from said cylinder to said chamber above the plug, a piston in said cylinder, said body having an opening extending from the fluid passage to said cylinder.

RICHARD H. WUNN.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,400,647 Westinghouse Dec. 20, 1921 1,403,756 Farmer Jan. 17, 1922 2,065,726l Nordstrom Dec. 29, 1936 2,321,233 Mueller June 8, 1943 2,368,183 Volpin Jan. 30, 1945 2,433,638 Volpin Dec. 30, 1947 FOREIGN PATENTS Number Country Date 256,098 Great Britain Aug. 5, 1926 

